<template>
  <div class="app-container">
    <h2 style="text-align: center;">发布新课程</h2>
    <el-steps :active="1" process-status="wait" align-center style="margin-bottom: 40px;">
      <el-step title="填写课程基本信息"/>
      <el-step title="创建课程大纲"/>
      <el-step title="提交审核"/>
    </el-steps>
    <el-form label-width="120px">
      <el-form-item label="课程标题">
        <el-input v-model="courseInfo.title" placeholder=" 示例：机器学习项目课：从基础到搭建项目视频课程。专业名称注意大小写"/>
      </el-form-item>
      <!-- 所属分类 TODO -->
      <el-form-item label="课程分类">
        <el-select
          v-model="courseInfo.subjectParentId"
          placeholder="请选择一级分类"
          @change="subjectOneLevel">
          <el-option
            v-for="subject in subjectOneList"
            :key="subject.id"
            :label="subject.title"
            :value="subject.id"/>
        </el-select>
        <el-select
          v-model="courseInfo.subjectId"
          placeholder="请选择二级分类">
          <el-option
            v-for="subjectq in subjectTwoList"
            :key="subjectq.id"
            :label="subjectq.title"
            :value="subjectq.id"/>
        </el-select>
      </el-form-item>
      <!-- 课程讲师 TODO -->
      <!-- 课程讲师 -->
      <el-form-item label="课程讲师">
        <el-select
          v-model="courseInfo.teacherId"
          placeholder="请选择">

          <el-option
            v-for="teacher in teacherList"
            :key="teacher.id"
            :label="teacher.name"
            :value="teacher.id"/>

        </el-select>
      </el-form-item>

      <el-form-item label="总课时">
        <el-input-number :min="0" v-model="courseInfo.lessonNum" controls-position="right" placeholder="请填写课程的总课时数"/>
      </el-form-item>
      <!-- 课程简介 TODO -->
      <!-- 课程简介-->
      <el-form-item label="课程简介">
        <tinymce :height="300" v-model="courseInfo.description"/>
      </el-form-item>
      <!-- 课程封面 TODO -->
      <el-form-item label="课程封面">
        <el-upload
          :show-file-list="false"
          :on-success="handleAvatarSuccess"
          :before-upload="beforeAvatarUpload"
          :action="BASE_API+'/edu/oss/file'"
          class="avatar-uploader">
          <img :src="courseInfo.cover">
        </el-upload>
      </el-form-item>
      <el-form-item label="课程价格">
        <el-input-number :min="0" v-model="courseInfo.price" controls-position="right" placeholder="免费课程请设置为0元"/>
        元
      </el-form-item>
      <el-form-item>
        <el-button :disabled="saveBtnDisabled" type="primary" @click="saveOrUpdate">保存并下一步</el-button>
      </el-form-item>
    </el-form>
  </div>
</template>
<script>
  import course from '@/api/edu/course'
  import subject from '@/api/edu/subject'
  import Tinymce from '@/components/Tinymce'

  export default {
    components: {Tinymce},
    data() {
      return {
        saveBtnDisabled: false, // 保存按钮是否禁用
        teacherList: [],
        subjectOneList: [],
        subjectTwoList: [],
        BASE_API: process.env.BASE_API,
        courseId: '',
        courseInfo: {
          title: '',
          subjectId: '',
          subjectParentId: '',
          teacherId: '',
          lessonNum: 0,
          description: '',
          cover: '/static/1.jpg',
          price: 0
        }
      }
    },
    created() {
      if (this.$route.params && this.$route.params.id) {
        this.courseId = this.$route.params.id
        this.getCourseIdInfo()
      } else {
        this.getOneSubject()
        this.getListTeacherData()
      }
    },
    watch: {
      // 监听
      $route(to, from) {
        this.courseInfo = {}
      }
    },
    methods: {
      // 根据课程id查询
      getCourseIdInfo() {
        course.getCourseInfoData(this.courseId).then(response => {
          this.courseInfo = response.data.courseInfoVO
          //1 查询所有的分类，包含一级和二级
          subject.getAllSubjectData()
            .then(response => {
              //2 获取所有一级分类
              this.subjectOneList = response.data.list
              //3 把所有的一级分类数组进行遍历，
              for(var i=0;i<this.subjectOneList.length;i++) {
                //获取每个一级分类
                var oneSubject = this.subjectOneList[i]
                //比较当前courseInfo里面一级分类id和所有的一级分类id
                if(this.courseInfo.subjectParentId == oneSubject.id) {
                  //获取一级分类所有的二级分类
                  this.subjectTwoList = oneSubject.children
                }
              }
            })
          //初始化所有讲师
          this.getListTeacherData()
        })
      },
      handleAvatarSuccess(res, file) {
        this.courseInfo.cover = res.data.url
      },
      beforeAvatarUpload(file) {
        const isJPG = file.type === 'image/jpeg'
        const isLt2M = file.size / 1024 / 1024 < 2
        if (!isJPG) {
          this.$message.error('上传头像图片只能是 JPG 格式!')
        }
        if (!isLt2M) {
          this.$message.error('上传头像图片大小不能超过 2MB!')
        }
        return isJPG && isLt2M
      },
      // 点击某个一级分类，触发change事件，显示对应的二级分类
      subjectOneLevel(value) {
        // value就是一级分类的id值
        for (var i = 0; i < this.subjectOneList.length; i++) {
          var subjectOne = this.subjectOneList[i]
          if (value === subjectOne.id) {
            this.subjectTwoList = subjectOne.children
            // 把二级分类id值清空
            this.courseInfo.subjectId = ''
          }
        }
      },
      // 查询所有的一级分类
      getOneSubject() {
        subject.getAllSubjectData().then(response => {
          this.subjectOneList = response.data.list
        })
      },
      getListTeacherData() {
        course.getListTeacher().then(response => {
          this.teacherList = response.data.items
        })
      },
      addCourse() {
        course.addCourseInfo(this.courseInfo).then(response => {
          this.$message({
            type: 'success',
            message: '添加课程信息成功!'
          })
          this.$router.push({path: '/course/chapter/' + response.data.courseId})
        })
      },
      updateCourse() {
        course.updateCourseInfoData(this.courseInfo).then(response => {
          this.$message({
            type: 'success',
            message: '修改课程信息成功!'
          })
          this.$router.push({path: '/course/chapter/' + this.courseId })
        })
      },
      saveOrUpdate() {
        //判断是添加还是修改
        if (!this.courseInfo.id) {
          this.addCourse()
        }else {
          this.updateCourse()
        }
      }
    }
  }
</script>
<style scoped>
  .tinymce-container {
    line-height: 29px;
  }
</style>
